1. Field of the Invention
The present invention relates generally to methods for stripping photoresist layers employed within microelectronics fabrications. More particularly, the present invention relates to methods for facilitating stripping of photoresist layers employed within microelectronics fabrications.
2. Description of the Related Art
Microelectronics fabrications are formed from microelectronics substrates over which are formed patterned microelectronics conductor layers which are separated by microelectronics dielectric layers.
In the process of forming microelectronics devices and patterned microelectronics layers, such as but not limited to patterned microelectronics conductor layers, within microelectronics fabrications, it is common in the art of microelectronics fabrication to employ patterned photoresist layers as mask layers for forming those microelectronics devices and patterned microelectronics layers from corresponding blanket microelectronics layers.
While the use of patterned photoresist layers as mask layers when forming microelectronics devices and patterned microelectronics layers from corresponding blanket microelectronics layers within microelectronics fabrications is thus quite common in the art of microelectronics fabrication, the use of patterned photoresist layers as mask layers when forming microelectronics devices and patterned microelectronics layers from corresponding blanket microelectronics layers within microelectronics fabrications is not without problems within the art of microelectronics fabrication. Specifically, it is common in the art of microelectronics fabrication for patterned photoresist layers which have been employed as mask layers for forming microelectronics devices and patterned microelectronics layers from corresponding blanket microelectronics layers often to be particularly difficult to strip from a microelectronics device or patterned microelectronics layer whose fabrication is facilitated employing the patterned photoresist layer. Typical microelectronics fabrication processes which provide patterned photoresist layers which are difficult to strip include but are not limited to reactive ion etch (RIE) plasma etch processes and ion implantation processes.
It is thus towards the goal of providing within the art of microelectronics fabrication methods which facilitate stripping of patterned photoresist layers, and particularly methods which facilitate stripping of patterned photoresist layers which have been employed as mask layers for forming microelectronics devices and patterned microelectronics layers from corresponding blanket microelectronics layers within microelectronics fabrications, that the present invention is directed.
Various methods have been disclosed in the art of microelectronics fabrication for forming and stripping patterned photoresist layers which may be employed as mask layers for fabricating microelectronics devices and patterned microelectronics layers within microelectronics fabrications.
For example, Wooton et al., in U.S. Pat. No. 5,496,438, discloses a method for stripping from a patterned metal layer within a microelectronics fabrication, while not staining the patterned metal layer, a patterned photoresist layer employed as a patterned photoresist etch mask layer when forming the patterned metal layer from a blanket metal layer while employing a reactive ion etch (RIE) plasma etch method which employs a corrosive etchant gas composition. Within the method, the patterned photoresist layer is stripped within an oxygen gas plasma for a period of time and at a sufficiently high temperature such that substantially all of the residual corrosive gas absorbed within the patterned photoresist layer is removed, but where the temperature is below a temperature at which the patterned metal layer begins to flow.
In addition, Nishina et al., in U.S. Pat. No. 5,503,964, discloses an oxygen containing plasma stripping method for stripping from a semiconductor substrate a patterned photoresist layer which is employed as a patterned photoresist ion implantation mask layer for forming an ion implanted region within the semiconductor substrate, where the oxygen containing plasma stripping method is employed without use of a reducing material, such as hydrogen, within the oxygen containing plasma stripping method. The method employs an ultraviolet radiation hardening of the patterned photoresist layer prior to employing the ultraviolet radiation hardened patterned photoresist layer as the patterned ion implantation mask layer, where the ultraviolet radiation hardening precludes formation within the ultraviolet radiation hardened patterned photoresist layer of ion implanted species whose removal would otherwise typically be effected with use of the reducing material.
Further, Kishimura, in U.S. Pat. No. 5,591,654, discloses a method for fabricating a patterned photoresist layer with enhanced dimensional integrity when employed as a patterned photoresist ion implantation mask layer within a semiconductor integrated circuit microelectronics fabrication. The method employs a thermal baking of a photoexposed blanket photoresist layer from which is formed the pattered photoresist layer prior to developing the photoexposed blanket photoresist layer to form the patterned photoresist layer, as well as a thermal baking of the patterned photoresist layer immediately after being developed from the photoexposed blanket photoresist layer.
Still further, Li, in U.S. Pat. No. 5,651,860, discloses a method for stripping from a semiconductor integrated circuit microelectronics fabrication a patterned photoresist layer which was employed as a patterned photoresist ion implantation mask layer for forming an ion implanted region within the semiconductor substrate. The method employs a hydrogenation of the patterned photoresist layer to form a hydrogenated patterned photoresist layer, prior to stripping from the microelectronics fabrication the hydrogenated ion implanted patterned photoresist layer through use of a conventional method.
Finally, Hung et al., in U.S. Pat. No. 5,770,523, discloses a method for stripping from a patterned metal layer within a microelectronics fabrication a patterned photoresist layer employed as a reactive ion etch (RME) plasma etch mask layer for forming the patterned metal layer. The method first employs stripping from the patterned photoresist layer a surface layer of the patterned photoresist layer within a plasma employing fluorine containing gases under conditions sufficient such that the remainder of the patterned photoresist layer may be stripped employing an oxygen containing plasma stripping method.
Desirable in the art of microelectronics fabrication are additional methods and materials which may be employed to strip patterned photoresist layers formed within microelectronics fabrications. More particularly desirable in the art of microelectronics fabrication are additional methods and materials which may be employed to strip patterned photoresist layers within microelectronics fabrications, where the patterned photoresist layers have been employed as patterned photoresist etch mask layers and patterned photoresist ion implantation mask layers.
It is towards the foregoing objects that the present invention is both generally and more specifically directed.
A first object of the present invention is to provide a method for stripping from a microelectronics fabrication a patterned photoresist layer.
A second object of the present invention is to provide a method in accord with the first object of the present invention, where the patterned photoresist layer is employed as a patterned photoresist etch mask layer for forming a patterned layer within the microelectronics fabrication.
A third object of the present invention is to provide a method in accord with the first object of the present invention, where the patterned photoresist layer is employed as a patterned photoresist ion implantation mask layer for forming an ion implanted region within an ion implanted layer formed beneath the patterned photoresist layer.
A fourth object of the present invention is to provide a method in accord with the first object of the present invention, the second object of the present invention or the third object of the present invention, which method is readily commercially implemented.
In accord with the objects of the present invention, there is provided a method for stripping from a microelectronics fabrication a patterned photoresist layer. To practice the method of the present invention, there is first provided a substrate. There is then formed over the substrate a target layer. There is then formed upon the target layer a patterned positive photoresist layer. There is then processed the target layer while employing the patterned positive photoresist layer as a mask layer to thus form from the target layer a processed target layer and to form from the patterned positive photoresist layer a processed patterned positive photoresist layer. There is then photoexposed the processed patterned positive photoresist layer to form a photoexposed processed patterned positive photoresist layer with enhanced solubility of the photoexposed processed patterned positive photoresist layer within a solvent. Finally, there is then stripped from the processed target layer the photoexposed processed patterned positive photoresist layer while employing the solvent.
There is provided by the present invention a method for stripping from a microelectronics fabrication a patterned photoresist layer. The method of the present invention realizes the forgoing object by employing when stripping the patterned photoresist layer in accord with the present invention a patterned positive photoresist layer which is employed as a mask layer when processing a target layer formed beneath the patterned positive photoresist layer. A processed patterned positive photoresist layer formed from the patterned positive photoresist layer incident to processing the target layer is then photoexposed to form a photoexposed processed patterned positive photoresist layer which exhibits an enhanced solubility within a solvent which is then employed to strip the photoexposed processed patterned positive photoresist layer from the processed target layer.
The present invention may be employed where: (1) the patterned photoresist layer is employed as a patterned photoresist etch mask layer for forming a patterned layer within a microelectronics fabrication; or (2) the patterned photoresist layer is employed as a patterned photoresist ion implantation mask layer for forming an ion implanted region within an ion implanted layer formed beneath the patterned photoresist layer. The present invention does not discriminate with respect to the use of a patterned photoresist layer with respect to whether the patterned photoresist layer is employed as a patterned photoresist etch mask layer or as a patterned photoresist ion implantation mask layer within a microelectronics fabrication. Thus, provided that the patterned photoresist layer is a patterned positive photoresist layer which is susceptible to an increase in solubility within a solvent when photoexposed to form a photoexposed processed patterned positive photoresist layer, the patterned photoresist layer may be formed as a mask layer including but not limited to a patterned photoresist etch mask layer or a patterned photoresist ion implantation mask layer when processing various types of target layers formed beneath the patterned photoresist layer.
The method of the present invention is readily commercially implemented. The present invention employs methods and materials as are otherwise generally known in the art of microelectronics fabrication. Since it is a process ordering and process control within the present invention which provides at least in part the present invention, rather than the existence of methods and materials which provides the present invention, the method of the present invention is readily commercially implemented.